Agent Threat Rules: Open detection rule format for AI agent security threats

Came across this open detection rule format for AI agent security threats. The interesting part is that it treats agent threats more like Sigma/YARA style detection: YAML rules for things like prompt injection, tool-call arguments, SKILL.md content, agent manipulation, skill compromise, and context exfiltration. That feels like a useful direction because agent security is still very scattered right now. Everyone talks about prompt injection and tool abuse, but there is not much shared language for detection rules, test cases, and repeatable coverage. The article also notes a big limitation: regex/rule-based detection can catch structured patterns, but paraphrased or semantic attacks still slip through. So this is not a full answer by itself. Curious what people here think. Do agent systems need an open rule format like this, or will detection need to be mostly runtime/context based instead of signature based?